Apparatus and method for deploying equipment into a wellbore

ABSTRACT

A method for lubricating a downhole tool into a wellbore with a lubricator assembly comprising a hydraulic cylinder with a cylinder and a rod and a pressure isolation assembly connected to the bottom of the cylinder of the hydraulic cylinder. The pressure isolation assembly has a base, a top, a plurality of posts supporting the top in a spaced apart relationship to the base, and a seal assembly supported by the base and configured to seal around the rod. The seal assembly includes a packing flange body having a flange portion and a tubular portion formed as a one piece unit. The flange portion extends across a portion of a lower side of the base and the tubular portion extends through base. The rod extends through the seal assembly of the pressure isolation assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/905,339 filed Nov. 18, 2013, which is expressly incorporated herein by reference in its entirety.

BACKGROUND

Coiled tubing is often used to deploy downhole assembly. Coiled tubing can be defined as any continuously-milled tubular product manufactured in lengths that require spooling onto a take-up reel. Although initially used primarily for well cleanout and acid stimulation applications, coiled tubing is now used in other applications, including well unloading, fishing, tool conveyance, setting plus and retrieving plugs. The term “downhole tool” or “downhole assembly” refers generally to the downhole assembly that is deployed and used in a subterranean well. Electrical submersible pumps, jars, motors, fishing tools, and monitoring devices are common examples of downhole assembly.

Coiled tubing units typically include an injector head that is suspended above the wellhead by a crane or derrick. The injector head provides the surface drive force to run and retrieve the coiled tubing from the well. The injector head is often used in conjunction with a stripper and a blowout preventer. The stripper is typically located between the injector head and the blowout preventer and provides the primary operational seal between pressurized wellbore fluids and the surface environment. The blowout preventer may include one or more rams that perform various functions, including supporting the hanging coiled tubing, sealing around the coiled tubing and shearing the coiled tubing.

One of the drawbacks of using coiled tubing in conjunction with downhole assembly is the process used to connect the downhole assembly to the coiled tubing before lowering the downhole assembly into the well. In the past, a conventional lubricator was used to load tools before running the tools into the live well. The lubricator is a long, high-pressure pipe that is fitted between the top of a wellhead and the bottom of the injector head. The tools are assembled inside the lubricator and connected to the coiled tubing. The lubricator is then pressurized to wellbore pressure and the assembled tools are deployed through the wellhead in the well.

While generally effective, the prior art method of lubricating tools into the well suffers significant drawbacks. Most significantly, the use of a lubricator raises the injector head high above the wellbore for the duration of the coiled tubing operation. This requires the use of large cranes or derricks that decrease the cost effectiveness and efficiency of the coiled tubing deployment. Many well sites are too remote or too small to support the use of large cranes or derricks. Furthermore, elevated injector heads are unstable in high winds and pose an increased risk to operators and equipment.

In light of the shortcomings of the existing art, a need exists for an improved apparatus and method for lubricating and injecting downhole assembly into a wellbore. The inventive concepts disclosed herein are directed to these and other deficiencies in the prior art.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a deployment assembly constructed in accordance with the inventive concepts disclosed herein.

FIG. 2 is a side elevational view of the deployment assembly of FIG. 1

FIG. 3 is a top plan view of the deployment assembly of FIG. 1.

FIG. 4 is a perspective view of a portion of a lubricator assembly.

FIG. 5 is an exploded, elevational view the portion of the lubricator assembly illustrated in FIG. 5.

FIG. 6 is an enlarged view of FIG. 5.

FIG. 7A is a side elevational view of the lubricator assembly.

FIG. 7B is a cross-sectional view of a pressure isolation assembly taken along line 7B-7B of FIG. 7A.

FIG. 8 is an elevational view of the lubricator assembly shown mounted on a wellhead.

FIG. 9 is a cross sectional view taken along line 9-9 of FIG. 8.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Before explaining at least one embodiment of the inventive concepts disclosed herein in detail, it is to be understood that the inventive concepts are not limited in their application to the details of construction and the arrangement of the components or steps or methodologies set forth in the following description or illustrated in the drawings. The inventive concepts disclosed herein are capable of other embodiments, or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting the inventive concepts disclosed and claimed herein in any way.

In the following detailed description of embodiments of the inventive concepts, numerous specific details are set forth in order to provide a more thorough understanding of the inventive concepts. However, it will be apparent to one of ordinary skill in the art that the inventive concepts within the instant disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the instant disclosure.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements, and may include other elements not expressly listed or inherently present therein.

Unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B is true (or present).

In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments disclosed herein. This is done merely for convenience and to give a general sense of the inventive concepts. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

As used herein, qualifiers like “substantially,” “about,” “approximately,” and combinations and variations thereof, are intended to include not only the exact amount or value that they qualify, but also some slight deviations therefrom, which may be due to manufacturing tolerances, measurement error, wear and tear, stresses exerted on various parts, and combinations thereof, for example.

Finally, as used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

Referring now to the drawings, FIGS. 1-3 illustrate a lubricator assembly 100 shown incorporated in a deployment assembly 10. The lubricator assembly 100 serves to lubricate and inject downhole assemblies into a wellbore under pressure. “Downhole assembly” refers herein generally to downhole assembly that is deployed and used in a subterranean well. Electrical submersible pumps, jars, motors, fishing tools, and monitoring devices are common examples of downhole assemblies. As best illustrated in FIGS. 8 and 9, the lubricator assembly 100 may include a hydraulic cylinder 102, a pressure isolation assembly 104, a spool 106, and a blowout preventer 108. The blowout preventer 108 is to be connected to the top of a wellhead 110 (FIGS. 8 and 9).

Returning now to FIGS. 1-3, in one embodiment, the deployment assembly 10 may include a portable trailer 12 configured to support the lubricator assembly 100. The lubricator assembly 100 may be supported on the trailer 12 in such a way that the lubricator assembly 100 may be positioned in a horizontal orientation (FIGS. 2 and 3) for transport and in a vertical position (FIG. 1) wherein the lubricator assembly 100 may be supported by a derrick or crane (not shown) sufficient to lift and support the lubricator assembly 100 from the trailer and position the lubricator 100 over the wellhead 110 (shown in FIG. 8) in a manner to be discussed in further detail below. It will be understood, however, that the lubricator assembly 100 can alternatively be used in offshore applications and mounted on a boat or barge.

To assist in the assembly of the downhole assemblies, the deployment assembly 10 may further include a make-up and testing assembly 14 (referred to as “assembly 14” hereafter). The assembly 14 may include a tong boom 16 supported on the trailer 12 and moveable between a horizontal transport position (FIGS. 2 and 3) and a vertical position (FIG. 1). The tong boom 16 supports a tong trolley assembly 18 which is configured for connecting and disconnecting (threading and unthreading) tubular members, such as pipe joints. The tong trolley assembly 18 is slidably supported on the tong boom 16 so that the tong trolley assembly 18 is selectively moveable along the tong boom 16 to a desired height. Any suitable mechanism may be used to move the tong trolley assembly 18 along the tong boom 16. For example, the tong boom 16 may include a cable and pulley system (not shown).

The tong trolley assembly 18 may include a power tong 20 and at least one backup assembly 22. Any suitable power tong and back up tong may be utilized. However, in one embodiment, the power tong 20 and backup assembly 22 may be configured as described in U.S. 61/730,266, which is hereby expressly incorporated herein by reference.

The deployment assembly 10 may further include a dynamometer or “dyno” 24 for measuring force, moment of force (torque), or power of a motor (not shown) which is part of a downhole assembly prior to inserting the downhole assembly into the wellbore. The dyno 24 may be supported at the lower end of the tong boom 16.

The deployment assembly 10 may further include a crane 26 positioned in a way that the crane 26 may be utilized to lift and move the various parts of a downhole assembly into a position adjacent the tong boom 16, as needed. The deployment assembly 10 may also include at least on liquid storage tank 28 for storing a volume of liquid. In one embodiment, the volume of liquid stored in the liquid storage tank 28 may be used to pressure test varies pieces of equipment, such as blowout preventer 108. The deployment assembly 10 may also include a suitable power pack 30 which may include a hydraulic pump 32 and a diesel engine 34 and suitable electronics for recording data obtained from components of the deployment assembly 10.

While the deployment assembly 10 is shown as being mounted on a flatbed trailer 12, it is to be understood that the assembly 14 and the lubricator assembly 100 may be mounted on separate trailers (not shown). Further, the various components may be disassembled for transport or storage, and may be transported and assembled at any desired location, as will be understood by persons of ordinary skill in the art having the benefit of the instant disclosure.

Referring now to FIG. 8, the blowout preventer 108 may be a standard blowout preventer used in coiled tubing operations and should be selected based on the particular requirements of specific applications. The blowout preventer 108 may include a pair of internal rams. The blowout preventer 108 may also include one or more pairs of shear rams or blind rams. The blowout preventer may also be attached to other blowout preventers.

The lubricator assembly 100 is used to insert a downhole assembly, such as downhole assembly 138 (FIG. 9), into the wellbore. The downhole assembly 138 may be a single component, or alternatively made up of multiple components 138 a, 138 b, and 138 c that connect together to form the downhole assembly 138. It will be understood that the downhole assembly 138 may be made up of fewer components or more components than are shown in FIG. 9.

The spool 106 may include one or more spool segments 106 a and 106 b. In the embodiment illustrated herein, the spool segment 106 a may be function has an adapter between spool segment 106 b and the pressure isolation assembly 104. The spool 106 is designed to contain the downhole assembly 138 prior to the insertion of the downhole assembly 138 into the wellbore. The number of spool segments depends on the length of the downhole assembly 138. Each spool segment 106 a and 106 b may be a high-pressure spacer spool. In one embodiment, the spool 106 may be 30 feet in length, and the spool segments are installed in series.

The hydraulic cylinder 102 includes a cylinder 114 having a bore 116, a rod 118 and a seal assembly (not shown). The hydraulic cylinder 102 is connected to the hydraulic power pack 30 or hydraulic pump (not shown) and, unless otherwise specified, is structurally and functionally similar to conventional hydraulic rams.

The rod 118 may be constructed in modular rod segments such that additional lengths can be added or removed as needed as spool segments are added and removed, as discussed below.

As illustrated, the hydraulic cylinder 102 may be supported by a cage 121 to protect the hydraulic cylinder 102 and its various components during transport, as well as the rigging up and rigging down process.

The lubricator assembly 100 may also include a connector sub 136 (FIG. 9) that serves as a joint between the distal end of the rod 118 and the connected downhole assembly 138. In one embodiment, the connector sub 136 is configured as a “pup-joint” with opposing ends capable of being secured to the pressure isolation assembly 104 and the upper end of the spool 106. The functionality of the connector sub 136 is discussed below.

As shown in greater detail in FIGS. 5-7, the pressure isolation assembly 104 includes a base 122, a top 124, and a series of support posts 126. The top 124 of the pressure isolation assembly 104 may be connected to the cylinder 114 of the hydraulic cylinder 102. In one embodiment, the pressure isolation assembly 104 is rigidly fixed to the hydraulic cylinder 102 to facilitate transport.

The pressure isolation assembly 104 further includes a seal assembly 127. The seal assembly 127 is configured to seal around the rod 118 to retain pressure inside the spool 106. The seal assembly 127 may include a packing flange body 128, a packing spring 129, a lower bushing 130, a series of packings 131 separated by spacers 132, an upper bushing 133, and packing gland nut 134.

The packing flange body 128 includes a flange portion 135 and a tubular portion 136 machined as a one-piece unit. The packing spring 129, lower bushing 130, the packings 131, and upper bushing 133 are housed in the tubular portion 136, and the packing gland nut 134 engages the tubular portion 136 of the packing flange body 128 to affect the seal about rod 118.

The flange portion 136 is configured to extend across a portion of a lower side of the base 122 and includes a plurality of holes 137 for securing the packing flange body 128 between the base 122 and the top spool segment 106 a with fasteners of sufficient strength to withstand the stresses encountered when the lubricator 100 is in a horizontal position for transport. Examples of suitable fasteners are 1⅜ inch bolts (not shown). The flange portion 136 may be secured to the base 122 in any suitable fashion, such as with fasteners or by welding. The flange portion 130 may include an annular groove 139 for receiving a ring seal (not shown) adapted to provide a suitable seal between the packing flange body 128 and the top spool segment 106 a. In one embodiment, the lubricator assembly 100 is used to assemble and load the downhole assembly 138 before the downhole assembly 138 is connected to coiled tubing and deployed in the well. The use of the lubricator assembly 100 obviates the need for a conventional lubricator under the coiled tubing injector head. The injector head can thereby be operated much closer to the ground with smaller equipment and with reduced risk to person and property.

In an exemplary rig-up procedure, the blowout preventer 108 is secured to the wellhead 110. Next, the downhole assembly 138 is assembled and placed inside the spacer spool 106. The downhole assembly 138 may be assembled and tested using the assembly 14 and positioned in the spool using the crane 26 or other device. Once the downhole equipment 138 is completely assembled, the connector sub 136 is attached to the top of the downhole equipment 138 and the bottom of the hydraulic rod 118.

In an alternate embodiment, the hydraulic rod 118 is first connected to the connector sub 136, which in turn, is connected to the top component 138 a within the downhole equipment 138. The next component 138 b of the downhole equipment 138 is then connected to the top component 138 a. Once the length of the downhole equipment 138 is greater than the length of the first spool segment 106 a, the downhole equipment 138 is placed in the first spool segment 106 a, and the spool segment 106 a is secured to the pressure isolation assembly 104. In this fashion, additional spacer spool segments are added to the top spacer spool segment 106 a as the length of the downhole equipment 138 increases. To facilitate assembly, the rod 118 can be extended and retracted to provide easier access to the downhole equipment 138.

Once the downhole assembly 138 is assembled, tested and positioned in the spacer spool 106, the spacer spool 106 can be secured between the blowout preventer 108 and the pressure isolation assembly 104. Next, the spacer spool 106 is pressurized to wellbore pressure. In one embodiment, the spacer spool 106 is pressurized using a suitable compressed gas or fluid (e.g., methanol) stored on the trailer 12. Alternatively, the spacer spool 106 can be pressurized with a bypass line connected directly to the wellbore.

When the pressure inside the spacer spool 106 is balanced with the wellbore pressure, the operator moves a master valve on the wellhead to full open. The hydraulic assembly 102 is then activated to push the downhole assembly 138 through the blowout preventer 108 and the wellhead 110 into the well. Once the connector sub 136 reaches the blowout preventer 108, the internal rams 112 are closed to lock the downhole assembly 138 in place. The travel of the hydraulic rod 118 required to move the connector sub 136 through the blowout preventer 108 is measured, preferably with a counter wheel 140 or digital encoder, and recorded.

Next, the pressure in the spacer spool 106 is released and the spacer spool segments 106 a-106 b are disconnected from the blowout preventer 108. The rod 118 is then disconnected from the connector sub 136, and the depressurized spacer spool segments 106 a-106 b, pressure isolation assembly 104 and hydraulic assembly 102 are moved out of the way or rigged-down. At this point in the operation, the wellbore pressure is retained by the blowout preventer 108, and the downhole assembly 138 is suspended from the connector sub 136. The connector sub 136 is captured by the internal rams of the blowout preventer 108 with the top portion of the connector sub 136 extending above the top of the blowout preventer 108.

Coiled tubing (not shown) is then attached to the exposed end of the connector sub 136 and to a coiled tubing injector head (not shown). Any intervening components, such as additional blowout preventers (not shown), are attached to the top of the blowout preventer 108. Once the intervening components are brought to wellbore pressure, the internal rams 112 are opened and the coiled tubing injector head deploys the downhole assembly 138 into the well. At the end of the coiled tubing operation, the coiled tubing is retracted until the connector sub 136 is properly positioned adjacent the internal rams 112 of the blowout preventer 108. The internal rams 112 are closed around the connector sub 136, and the injector head and any intervening components can be removed from the well site. The spacer spool 106, hydraulic assembly 102 and pressure isolation assembly 104 are then installed and pressurized so that the downhole assembly 138 can be retracted into the spacer spool 106 for disassembly.

Thus, the lubricator 100 provides for a hydraulically powered lubricator that can be advantageously used to load downhole assembly in a well in a separate operation before connecting coiled tubing and a coiled tubing injector head. The apparatus and method provide an efficient and safe alternative to conventional lubricators used in combination with coiled tubing systems.

It is clear that the present invention is well adapted to carry out is objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments of the invention have been described in varying detail for purposes of disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention disclosed herein and in the associated drawings. For example, the hydraulic assembly 102, pressure isolation assembly 104 and blowout preventer 108 can be cooperatively used for fishing operations that require substantial “push-and-pull” forces. 

What is claimed is:
 1. A method for lubricating a downhole tool into a wellbore, the method comprising: installing a blowout preventer to the top of a wellhead, the blowout preventer includes internal rams; suspending a lubricator assembly over the wellhead, the lubricator assembly including a hydraulic cylinder with a cylinder and a rod and a pressure isolation assembly connected to the bottom of the cylinder of the hydraulic cylinder, wherein the pressure isolation assembly has a base, a top, a plurality of posts supporting the top in a spaced apart relationship to the base, and a seal assembly supported by the base and configured to seal around the rod, the seal assembly includes a packing flange body having a flange portion and a tubular portion formed as a one piece unit, the flange portion extending across a portion of a lower side of the base and the tubular portion extending at least partially through base, the rod extending through the seal assembly of the pressure isolation assembly; assembling the downhole tool; connecting the assembled downhole tool to the rod; securing at least one spacer spool to the flange portion of the seal assembly of the pressure isolation assembly to encase the assembled downhole tool; connecting the spacer spool to the top of the blowout preventer; equalizing the pressure in the at least one spacer spool and the pressure in the wellbore; holding the pressure in the spacer spool with the seal assembly; activating the hydraulic cylinder to extend the rod and downhole tool through the blowout preventer; and suspending the downhole tool in the blowout preventer with the internal rams of the blowout preventer.
 2. The method of claim 1, further comprising: supporting the lubricator assembly on a trailer prior to suspending the lubricator assembly over the wellhead; and pressure testing the assembled downhole tool with a make-up and testing assembly supported by the trailer.
 3. The method of claim 2, further comprising assembling the downhole tool with the make-up and testing assembly prior to pressure testing the assembled downhole tool, wherein the make-up and testing assembly includes a tong boom supported by the trailer and supporting a tong trolley assembly configured to connect and disconnect portions of the tool assembly.
 4. A method for lubricating a downhole tool into a wellbore, the method comprising: assembling a downhole tool with a make-up and testing assembly supported by a trailer, the make-up and testing assembly including a tong boom supported by the trailer and supporting a tong trolley assembly configured to connect and disconnect portions of the tool assembly. installing a blowout preventer to the top of a wellhead, wherein the blowout preventer includes internal rams; supporting a lubricator assembly on the trailer in a horizontal orientation, the lubricator assembly including a hydraulic cylinder with a cylinder and a rod and a pressure isolation assembly connected to the bottom of the cylinder of the hydraulic cylinder, the pressure isolation assembly has a base, a top, a plurality of posts supporting the top in a spaced apart relationship to the base, and a seal assembly supported by the base and configured to seal around the rod; moving the lubricator assembly from the horizontal orientation to a vertical orientation with a crane supported by the trailer; suspending the lubricator assembly over the wellhead; connecting the assembled downhole tool to the rod; securing at least one spacer spool to the flange portion of the seal assembly of the pressure isolation assembly to encase the assembled downhole tool; connecting the spacer spool to the top of the blowout preventer; equalizing the pressure in the at least one spacer spool and the pressure in the wellbore; holding the pressure in the spacer spool with the seal assembly; activating the hydraulic cylinder to extend the rod and downhole tool through the blowout preventer; and suspending the downhole tool in the blowout preventer with the internal rams of the blowout preventer.
 5. The method of claim 4, further comprising: supporting the lubricator assembly on a trailer prior to suspending the lubricator assembly over the wellhead; and pressure testing the assembled downhole tool with the make-up and testing assembly supported by the trailer prior to connecting the assembled downhole tool to the rod.
 6. A method for lubricating a downhole tool into a wellbore, the method comprising: assembling a downhole tool with a make-up and testing assembly supported by a trailer, the make-up and testing assembly including a tong boom supported by the trailer and supporting a tong trolley assembly configured to connect and disconnect portions of the tool assembly. installing a blowout preventer to the top of a wellhead, wherein the blowout preventer includes internal rams; supporting a lubricator assembly on the trailer in a horizontal orientation, the lubricator assembly including a hydraulic cylinder with a cylinder and a rod and a pressure isolation assembly connected to the bottom of the cylinder of the hydraulic cylinder, wherein the pressure isolation assembly has a base, a top, a plurality of posts supporting the top in a spaced apart relationship to the base, and a seal assembly supported by the base and configured to seal around the rod, the seal assembly includes a packing flange body having a flange portion and a tubular portion formed as a one piece unit, the flange portion connected to and extending across a portion of a lower side of the base and the tubular portion extending at least partially through base, the rod extending through the seal assembly of the pressure isolation assembly; moving the lubricator assembly from the horizontal orientation to a vertical orientation with a crane supported by the trailer; suspending the lubricator assembly over the wellhead; connecting the assembled downhole tool to the rod; securing at least one spacer spool to the flange portion of the seal assembly of the pressure isolation assembly to encase the assembled downhole tool; connecting the spacer spool to the top of the blowout preventer; equalizing the pressure in the at least one spacer spool and the pressure in the wellbore; holding the pressure in the spacer spool with the seal assembly; activating the hydraulic cylinder to extend the rod and downhole tool through the blowout preventer; and suspending the downhole tool in the blowout preventer with the internal rams of the blowout preventer.
 7. The method of claim 6, further comprising: supporting the lubricator assembly on a trailer prior to suspending the lubricator assembly over the wellhead; and pressure testing the assembled downhole tool with the make-up and testing assembly supported by the trailer prior to connecting the assembled downhole tool to the rod. 